Obesity has become a major health concern, both nationally and internationally. The National Center for Health Statistics (NCHS) estimates that over 120 million Americans are overweight, including about 56% of the adult population. Of these, about 52 million are considered obese, as measured by a body mass index (BMI) of 30% or greater. In Europe, an estimated 77 million people are obese, as measured by the same standard. This problem is not limited to western nations, as many developing countries are reported to have obesity rates over 75% of the adult population.
Co-morbidities that are associated with obesity include, but are not limited to type II Diabetes, high blood pressure, sleep apnea, stroke and arthritis, the symptoms of which often tend to be lessened or alleviated upon loss of weight by a person so affected.
In the U.S., options for treatment of obesity are currently quite limited. Current treatment methodologies typically rely upon surgically introducing a “malabsorptive” environment in the gastro-intestinal tract, a restrictive environment, or a combination of these. One available treatment method is gastric bypass surgery and another is referred to as gastric banding (one of these techniques if referred to as the LAPBAND™ procedure). These procedures are limited to only those patients with a BMI over 40 (or over 35, with co-morbidities present).
Gastric bypass procedures incur a great deal of morbidity and create a malabsorptive state in the patient by bypassing a large portion of the intestines. Serious side effects, such as liver failure have been associated with this procedure, as well as chronic diarrhea. Another surgical procedure that has a high degree of morbidity associated with it is known as the “Gastric Bypass Roux-en-Y” procedure. This procedure reduces the capacity of the stomach by creating a smaller stomach pouch. The small space holds only about one ounce of fluid. A tiny stomach outlet is also surgically created to slow the speed at which food leaves the stomach. Staples are used to create a small (15 to 20 cc) stomach pouch, with the rest of the stomach being stapled completely shut and divided from the stomach pouch. The small intestine is divided just beyond the duodenum, brought up, and connected to the newly formed stomach pouch. In addition to the considerable morbidity associated with this procedure, other disadvantages include “dumping syndrome”, where stomach contents are literally “dumped” rapidly into the small intestine which may lead to nausea, weakness, sweating, faintness, and diarrhea; hernias resulting from the surgery; gallstones; leakage of the connection between the pouch and the intestine; stretching of the pouch that was formed; nutritional deficiencies; and possible dehiscence of the staples.
The LAPBAND™ is a band that, when placed, encircles the fundus-cardia junction and is inflatable to constrict the same. It does not reduce the volume of the stomach, but rather restricts passage of food into the stomach, the theory being that the patient will feel satiety with a much less volume of food than previously. Although the LAPBAND™ procedure is less invasive than a gastric bypass procedure, it also typically achieves less weight loss. Further, it is not a simple procedure and requires a substantial amount of training by a surgeon to become proficient in performing the procedure. Also, a substantial amount of dissecting and suturing is required because the pathway by which the band is introduced is not an existing pathway, and must be established by dissection. Great care is required to avoid blood vessels and nerves that may be in the intended pathway to be created by the dissection. After placing the band around the fundus-cardia junction, the ends of the band must be connected together and then it must be cinched down into place. Additionally, complications such as erosion at the fundus-cardia junction, slippage of the band from its intended location, nausea/vomiting, gastroesophageal reflux, dysphagia and lack of effectiveness in causing weight loss have been reported.
Intra-gastric balloons have also been placed, in an attempt to fill a portion of the volume in the stomach, with the theory being that it will then require less food than previously, to give the patient a sensation of fullness or satiety. This procedure involves delivery of a balloon (typically, trans-orally) to the interior of the stomach and inflation of the balloon to take up a portion of the volume inside the stomach. However, intra-gastric balloons may also lead to complications such as obstruction, vomiting and/or mucosal erosion of the inner lining of the stomach. The balloon can break down over extended exposure to the stomach's acids, and in some cases, after breaking down, the balloon translated through the intestines and caused a bowel obstruction.
Gastrointestinal sleeves have been implanted to line the stomach and/or a portion of the small intestines to reduce the absorptive capabilities of the small intestine and/or to reduce the volume in the stomach, by reducing the available volume to the tubular structure of the graft running therethrough. Although weight loss may be effective while these types of devices are properly functioning, there are complications with anchoring the device within the stomach/GI tract, as the stomach and GI tract function to break down things that enter into them and to move/transport them through. Accordingly, the integrity of the anchoring of the device, as well as the device itself may be compromised over time by the acids and actions of the stomach and GI tract.
A sleeve gastrectomy is an operation in which the left side of the stomach is surgically removed. This results in a much reduced stomach which is substantially tubular and may take on the shape of a banana. This procedure is associated with a high degree of morbidity, as a large portion of the stomach is surgically removed. Additionally, there are risks of complications such as dehiscence of the staple line where the staples are installed to close the surgical incisions where the portion of the stomach was removed. Further, the procedure is not reversible.
In the laparoscopic duodenal switch, the size of the stomach is reduced in similar manner to that performed in a sleeve gastrectomy. Additionally, approximately half of the small intestine is bypassed and the stomach is reconnected to the shortened small intestine. This procedure suffers from the same complications as the sleeve gastrectomy, and even greater morbidity is associated with this procedure due to the additional intestinal bypass that needs to be performed. Still further, complications associated with malabsorption may also present themselves.
An inflatable gastric device is disclosed in U.S. Pat. No. 4,246,893, in which a balloon is inserted anteriorly of the stomach and posteriorly of the left lobe of the liver. The balloon is then inflated to compress the stomach so that it fills with less food that would ordinarily be possible. Not only does this device compress the stomach, but it also compresses the liver, as seen in FIG. 5 of the patent, which may cause complications with the liver function. Additionally, the balloon is simply placed into this location, and there is no assurance that it will not migrate and lose its effectiveness in compressing the stomach to the degree intended. Still further, the balloon is of a simple spherical design, and, as such, extends pressure outwardly in all directions, 360 degrees in all planes. Accordingly, the liver is compressed just as much as the stomach is. Also, the compression forces against the stomach are not ideal, as the spherical balloon conformation does not match the conformation of the expanding stomach. The stomach is not spherical when expanded, or concave with a constant radius of curvature, but expands into a designated space that allows the fundus to expand preferentially more than other parts of the stomach.
Brazzini et al. in WO2005/18417 discloses at least two or more expandable devices used to treat obesity, in which the devices are inserted through the abdominal wall and anchored subcutaneously or to the stomach wall to exert pressure against the external surface of the stomach wall.
U.S. Patent Publication No. 2005/0261712 to Balbierz et al. describes capturing a device against the outer surface of the stomach wall to form a restriction that appears to function similarly to the restriction imposed by the LAPBAND™. The anchoring of the devices disclosed relies upon placement of features against the internal wall of the stomach to form an interlock with the device which is placed against the external wall of the stomach.
U.S. Patent Publication No. 2005/0267533 to Gertner discloses devices for treatment of obesity that use one or more anchoring mechanisms that are passed through the wall of the stomach to establish an anchor. The stomach is reduced in size by passing the devices through the stomach wall on opposite sides of the stomach and compressing the walls together to eliminate a portion of the interior space within the stomach. Gertner also discloses an embodiment in which an extra-gastric balloon is placed anteriorly of the stomach and attached to the abdominal wall using one of the anchoring mechanisms described.
U.S. Pat. No. 6,981,978 to Gannoe discloses devices for reducing the internal cavity of the stomach to a much smaller volume, which may be used to carry out a bypass procedure. Stapling is employed to isolate the smaller volume in the stomach, and thus the same potential disadvantages are present as with other stapling procedures described herein.
U.S. Pat. No. 6,186,149 to Pacella et al. describes an occluder device that can be used as a dietary control device (see FIG. 8C). The occluder device is placed against the wall of the stomach and inflated to press inwardly on the stomach wall. A frame is wrapped around the stomach wall and is inflated to press against the stomach wall. However, there is no disclosure of how the frame might be adjusted to maintain a position relative to the stomach wall as the size of the stomach varies.
Gastric reduction techniques have been attempted, such as by inserting instruments trans-orally and reducing the volume of the stomach by stapling portions of it together. However, this technique is prone to failure due to the staples pulling through the tissues (i.e., dehiscence) that they are meant to bind.
Techniques referred to as gastric pacing endeavor to use electrical stimulation to simulate the normal feedback mechanisms of a patient that signal the brain that the patient is full, or satiated. While these techniques are less invasive than some of the other existing treatments, statistics to date have shown that the amount of weight lost by using such techniques is less than satisfactory.
Currently marketed drugs for weight loss, such as XENICAL®, MERIDIA® and Phen fen have largely failed, due to unacceptable side effects and complications, and sometimes to an ineffective amount of weight loss. Other drugs that are on the horizon include ACCOMPLIA® and SYMLIN®, but these are, as yet, unproven.
The risk and invasiveness factors of currently available surgeries are often too great for a patient to accept to undergo surgical treatment for his/her obesity. Accordingly, there is a need for less invasive, yet effective surgical treatment procedures for morbidly obese patients (patients having a BMI of 35 or greater). Also, since the current surgical procedures are currently indicated only for those patients having a BMI of 40 or greater, or 35 or greater when co-morbidities are present, it would be desirable to provide a surgical procedure that would be available for slightly less obese patients, e.g., patients having a BMI of 30 to 35 who are not indicated for the currently available surgical procedures. It would further be desirable to provide a surgical procedure that would be indicated for obese patients having a BMI in the range of 30-35, as well as for more obese patients.